1. Field
The present disclosure relates generally to processing data and in particular to a method and apparatus for measuring current and voltage. Still more particularly, the present disclosure relates to a method and apparatus for measuring current and voltage of a solar array in space.
2. Background
Spacecraft are vehicles or devices designed for space flight or use in space. Spacecraft may be used for various purposes such as, for example, communications, earth observation, metrology, navigation, planetary exploration, and other suitable uses. A spacecraft has various subsystems that may vary depending on the particular purpose of the spacecraft. Spacecraft subsystems may include attitude determination and control, guidance, navigation, communications, telemetry and command, thermal control, propulsion, and power.
With respect to power, electrical power generation and distribution is typically required in a spacecraft. One typical power generation system is a solar array. A solar array consists of single or multiple solar panels which have a surface area that can be controlled to point towards the sun as a mechanism moves. More exposed surface area means that more electricity may be converted from light energy. A solar panel typically consists of multiple solar strings. A solar string is a group of solar cells connected in series.
Solar arrays may be monitored by collecting voltage and current data to determine whether the solar arrays are performing as predicted. The data collected may be used to create a current voltage (I-V) curve for evaluation. To create a high fidelity I-V curve, a large number of voltage and current data points are required. The data must also be collected in a short duration in order to minimize temperature effects on a solar cell voltage/current relationship. With the spacecraft in orbit, this large amount of data may typically be stored in the spacecraft and transmitted to earth through wireless communications at a later time.